With that, Coach Mike Tomlin of the Pittsburgh Steelers opened a season-ending news conference on Wednesday in which he addressed his team’s late-season collapse and the drama surrounding the superstar receiver Antonio Brown, all the while struggling to mask his discomfort.

“Extremely disappointed,” Tomlin said in summation of the season. “I think that’s a succinct assessment of it. The fact that we’re actually standing in this room says it all.”

The Steelers’ roller coaster of a season began with a 1-2-1 stretch, followed by a six-game winning streak that seemed to quell the early-season consternation, and then a collapse that dragged the team out of the playoff picture.

But things hit a new low early this week when it became clear that Brown had missed Sunday’s win over Cincinnati not because of a knee injury, as the team had said, but rather for disciplinary reasons.

Complicating matters was Brown’s use of social media this week, in which he seemed to be courting attention from the San Francisco 49ers: He followed the team’s Instagram account, posted an Instagram story about Jerry Rice being the greatest wide receiver of all time, and replied to a Twitter post by San Francisco’s George Kittle.

But Tomlin, closing out his 12th season with Pittsburgh, kept trying to bring the focus back to the team, insisting that no decisions had been made, that no disciplinary actions had been taken, and that Brown, regardless of his social media chatter, had not requested a trade.

“Distractions and things of that nature are part of the job, particularly in today’s N.F.L.,” Tomlin said. “I don’t run away from it; in fact, I embrace it.”

The Steelers have had no shortage of distractions in recent years, from the suspensions and contract holdouts of Le’Veon Bell — the superstar running back who sat out the entire 2018 season in hopes of negotiating a larger contract — to Brown’s occasional public disagreements with quarterback Ben Roethlisberger, to the team’s bizarre national anthem protest last season in which no one seemed to be on the same page.

Tomlin tried to explain the timeline around Brown’s absence on Sunday as clearly as possible. He said Brown sat out of the team’s practices last week with what was described as a sore knee, then was told on Friday to get an magnetic resonance imaging exam — a test Tomlin says was never performed. After Brown failed to communicate with the team on Friday night, Tomlin said, the Steelers made plans to face the Bengals without him.

Tomlin said Brown’s agent, Drew Rosenhaus, reached out Sunday in hopes of getting Brown onto the field, but Tomlin, who agreed to meet with Brown, said that “playing wasn’t on the menu” at that point.

When asked if it was the injury or a disciplinary action that kept Brown out on Sunday, Tomlin said, “He was absent due to injury and lack of information.”

Now the team must decide what to do with a 30-year-old wide receiver who is clearly still in his prime but who appears to be at something of an impasse with his coach.

Tomlin was asked about Brown’s social media usage, and he tried to make light of how much the news media likes to make a big deal of something that is not important to him. But Brown seemed to tweak his coach by posting a message to Twitter during the news conference that could be seen as a response to Tomlin’s comments.

Brown was still at the top of his game for Pittsburgh this season. He exceeded 100 receptions for an N.F.L.-record sixth consecutive season, and while he finished behind his teammate JuJu Smith-Schuster in catches and receiving yards — the first season he has not led the Steelers in both categories since 2012 — he scored a career-high 15 touchdowns.

But in a rare acknowledgment that distractions can sometimes get out of control, Tomlin said Brown’s situation could “certainly” get to the point where the receiver was more problematic than useful.

The issues with trading Brown are plentiful. There is the cap hit the team would take for moving him (a blow that would be softened by savings in future years), the question of how much value a team could get for an aging wide receiver, and the prospect of going into 2019 with neither Bell nor Brown.

But Tomlin said his team would “waddle in it right now,” letting this season’s failure sink in before making any decisions about next season. And while he intimated that it would be fair to say that Brown quit on the team, Tomlin said he was doing his best to keep some emotional distance from the issue.